U.S. Pat. No. 4,062,385, issued Dec. 13, 1977 to Katusha et al, shows a toner container having a containing portion with an opening on the bottom and a flange extending outward from the opening. A cover is slidably secured to the flange. A receiving apparatus for the container includes a sump cavity for receiving toner through the bottom of the container when the opening of the container is positioned directly above it. The container and cover are positioned beside the cavity and the container portion is slid off the cover and over the cavity with the flange sliding on a receiving surface that surrounds the cavity.
A problem with this system is that the leading edge of the flange as the container is slid to its position over the cavity has a tendency to skive toner associated with the cavity out of the cavity area and into the workings of the apparatus and into the air. Airborne toner or toner in the apparatus causes a myriad of problems with the apparatus and anyone working with the apparatus.